Transverse Beam Matching Application for SNS

An automated transverse beam matching application has been developed for the Spallation Neutron Source (SNS) beam transport lines. The application is written within the XAL Java framework and the matching algorithm is based on the simplex optimization method. Other functionalities, such as emittance calculated from profile monitor measurements (adopted from a LANL Fortran code), profile monitor display, and XAL on-line model calculation, are also provided by the application. Test results obtained during the SNS warm linac commissioning will be reported. A comparison between the emittances obtained from this application and an independent Trace-3D routine will also be shown.

INTRODUCTION

The SNS is designed to produce 1.4 MW of neutron power by bombarding a target with a high intensity proton beam. The beam optics should be carefully controlled in the linac and the accumulator ring to avoid unnecessary radiation activation due to beam loss. A beam optics control program has been developed within the XAL framework [1], [2] to provide better transverse matching in the transition regions between various sub-systems.